The present invention relates to differential drivers for producing accurate complementary output signals from skewed complementary logic input signals.
One of the difficulties in differential driver design is to generate symmetric outputs in which the two output waveforms cross each other at exactly 50% of the waveform rise or fall time, so as to be exactly complementary.
Much of the signal processing in a device may today be done in one or more CMOS chips. But, to accurately generate output waveforms that are exactly complementary, and that are suitable to drive an output load, it has been necessary to construct the output differential driver circuit of bipolar devices. Thus, the output differential driver for a CMOS processor must be a separate device from the CMOS processor.
CMOS single-ended input differential drivers have been produced that take a single logic input signal and generate substantially complementary output signals. But, the output signals produced tend to be skewed; namely, they are not exactly complementary.